how to make a composite primary key (java persistence annotation)

How to make it so that the table user_roles defines the two columns (userID, roleID) as a composite primary key. should be easy, just can't remember/find.

In user entity:

@ManyToMany(fetch = FetchType.LAZY)
@JoinTable(name = "user_roles")
public List<RoleDAO> getRoles() {
    return roles;
}

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Integer getUserID() {
    return userID;
}

In roles entity:

@ManyToMany(fetch = FetchType.LAZY)
@JoinTable(name = "user_roles")
public List<UserDAO> getUsers() {
    return users;
}

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Integer getRoleID() {
    return roleID;
}

Thank you.

** MORE INFO

So there is a third table user_roles (auto generated by above) that takes userID from user entity and roleID from roles entity. Now I need those two columns in the generated table (user_roles) to be a composite primary key.